VpsS requires the HPT LuxU to activate vps expression. (A) Expression of vpsL from a vpsLp-lacZ reporter in wild-type (Wt), ΔluxU, ΔVC1080, and ΔVC2038 strains grown to exponential phase in LB medium. (B) Expression of vpsL from a vpsLp-lacZ reporter in wild-type, ΔluxU, ΔVC1080, and ΔVC2038 strains harboring the vector (open bars) or pvpsS (filled bars). vpsS was overexpressed in LB medium supplemented with ampicillin and 0.2% arabinose. The error bars indicate standard deviations of eight technical replicates. The results of one representative experiment of four biological replicates are shown.